There are several free apps that support tversity, which also has a free "basic" version to run on the server side. Having said that, Plex is a joy to use and makes the whole thing so easy if you set up things correctly on the server side. I recommend spending the $4.99 on the app and making your life easier.

Another big thumbs up for Plex. Once you get the server set up, it will stream to almost anything anywhere. Product updates are frequent, the company rev team has generally been very good about listening to feedback and since it's your media on your PC as a server, you get control your destiny (so to speak).

Also keep in mind that as of a few weeks ago, the Plex client became a Universal Windows App, so your $4.99 gets you both the Windows Phone and Windows 8 Apps.